Quando utiliza a seguinte função:
setor_m.dissolve(by='NM_BAIRRO')
Ela retorna:
TopologyException: Input geom 0 is invalid: Self-intersection at or near point -43.250213293714594 -22.887739582871898 at -43.250213293714594 -22.887739582871898
TopologyException: Input geom 0 is invalid: Self-intersection at or near point -43.250213293714594 -22.887739582871898 at -43.250213293714594 -22.887739582871898
TopologyException: Input geom 0 is invalid: Self-intersection at or near point -43.250213293714594 -22.887739582871898 at -43.250213293714594 -22.887739582871898
ValueError: No Shapely geometry can be created from null value
O detalhe é que o crs está como EPSG:4326